The Virtual Instruments on mac are 64bit universal (intel & apple) including AU, VST2 and VST3
On windows, they are 64bit intel for VST2 and VST3.

Once you have unzipped the downloaded file and extract it to your desktop,
copy the entire folder including the PSS-680Big7.mse to your VST2/VST3 plugins folder.

If you are prompted to locate the instruments folder, do so.
You will only need to do this once.
The instrument file is the PSS-680Big7.mse file.

If you get no sound immediately, just close your DAW and restart.

Tested on WIN-10, Cubase 12.
I have no Possibility to Test it with a MAC.

Bonus:
MIDI File
Lossless transcodes of rom waves for your sampling delight.

Welcome back to 1988 Drums.

Greetings from Switzerland
LeWelsch Creative Head.